import { useEffect, useState } from 'react'
import { Link, useLocation, useNavigate } from 'react-router-dom'
import { useAuth } from '../context/AuthContext'
import {
  IconTicket,
  IconUsers,
  IconTargetArrow,
  IconReportMoney,
  IconScale,
  IconActivityHeartbeat,
  IconFolders,
  IconLayoutGrid,
  IconCalendar,
  IconSettings,
  IconLogout,
  IconLayoutSidebarLeftCollapse,
  IconLayoutSidebarLeftExpand,
  IconMessages,
  IconReceiptRefund,
  IconDiscount,
  IconMailCog,
} from '@tabler/icons-react'
import { serverpulsApi } from '../lib/serverpulsApi'
import { startsCollapsed } from '../lib/sidebar'
import { buildNavLinks } from '../lib/navLinks'
import { useSidebarCounts } from '../hooks/useSidebarCounts'

const ICONS = {
  tickets: <IconTicket />,
  planboard: <IconCalendar />,
  projects: <IconFolders />,
  services: <IconLayoutGrid />,
  customers: <IconUsers />,
  chat: <IconMessages />,
  gutschriften: <IconReceiptRefund />,
  angebote: <IconDiscount />,
  speicher: <IconMailCog />,
  leads: <IconTargetArrow />,
  finance: <IconReportMoney />,
  legal: <IconScale />,
  serverpuls: <IconActivityHeartbeat />,
  admin: <IconSettings />,
}

export default function Sidebar() {
  const { user, logout, isAdmin } = useAuth()
  const navigate = useNavigate()
  const location = useLocation()
  const [collapsed, setCollapsed] = useState(() => startsCollapsed())
  const [pulseLevel, setPulseLevel] = useState('ok')
  const counts = useSidebarCounts()

  // Serverpuls-Punkt: nur Admins, beim Laden und alle 5 Minuten; Fehler bleiben still
  useEffect(() => {
    if (!isAdmin) { setPulseLevel('ok'); return undefined }
    let dead = false
    const load = () => {
      serverpulsApi.overview()
        .then((o) => { if (!dead) setPulseLevel(o?.level || 'ok') })
        .catch(() => { if (!dead) setPulseLevel('ok') })
    }
    load()
    const iv = setInterval(load, 5 * 60 * 1000)
    return () => { dead = true; clearInterval(iv) }
  }, [isAdmin])

  const handleLogout = async () => {
    await logout()
    navigate('/login')
  }

  // Eintraege und Unterpunkte (Kunden -> Chat) aus lib/navLinks.js, Icons ueber key
  const links = buildNavLinks({ isAdmin, pulseLevel, counts })

  const isActive = (href) =>
    location.pathname === href || location.pathname.startsWith(href + '/')
  // Finanzen bleibt auch auf der Rueckkehrseite der Bankfreigabe (/finanzen/...) markiert
  const isLinkActive = (link) => isActive(link.href) || (link.also ? isActive(link.also) : false)

  return (
    <aside className={`side ${collapsed ? 'collapsed' : ''}`}>
      <div className="side-head">
        <Link to="/" className="side-logo" title="Webklar">W</Link>
        <div className="side-brand">
          Webklar
          <small>Ticket-Plattform</small>
        </div>
      </div>

      <nav className="side-nav">
        <div className="side-group">
          {links.map((link) => link.paused ? (
            <span
              key={link.href}
              className="side-link side-link-paused"
              title={`${link.label} (pausiert)`}
              aria-disabled="true"
            >
              {ICONS[link.key]}
              <span className="side-link-label">{link.label}</span>
            </span>
          ) : (
            <Link
              key={link.href}
              to={link.href}
              className={`side-link ${isLinkActive(link) ? 'active' : ''}`}
              title={link.label}
            >
              {ICONS[link.key]}
              <span className="side-link-label">{link.label}</span>
              {link.dot && link.dot !== 'ok' && (
                <span
                  className={`side-dot side-dot-${link.dot}`}
                  data-testid="sp-nav-dot"
                  title={link.dot === 'critical' ? 'Critical-Warnung aktiv' : 'Warnung aktiv'}
                />
              )}
            </Link>
          )).flatMap((item, i) => [
            item,
            ...(links[i].children || []).map((child) => (
              <Link
                key={child.href}
                to={child.href}
                className={`side-link side-sublink ${isActive(child.href) ? 'active' : ''}`}
                title={child.count > 0 ? `${child.label} (${child.count} ${child.key === 'chat' ? 'ungelesen' : 'offen'})` : child.label}
              >
                {ICONS[child.key]}
                <span className="side-link-label">{child.label}</span>
                {child.count > 0 && <span className="side-count">{child.count}</span>}
              </Link>
            )),
          ])}
        </div>
      </nav>

      <div className="side-foot">
        {user && (
          <div className="side-link" title={user.name || user.email} style={{ cursor: 'default' }}>
            <div className="side-logo" style={{ width: 28, height: 28, fontSize: 12, background: 'linear-gradient(135deg,#667eea,#764ba2)' }}>
              {(user.name || user.email || '?').charAt(0).toUpperCase()}
            </div>
            <span className="side-link-label text-ellipsis">{user.name || user.email}</span>
          </div>
        )}
        <button className="side-toggle" onClick={handleLogout} title="Logout">
          <IconLogout size={20} />
          <span className="side-link-label">Logout</span>
        </button>
        <button className="side-toggle" onClick={() => setCollapsed((c) => !c)} title="Menue ein-/ausklappen">
          {collapsed ? <IconLayoutSidebarLeftExpand size={20} /> : <IconLayoutSidebarLeftCollapse size={20} />}
          <span className="side-link-label">Einklappen</span>
        </button>
      </div>
    </aside>
  )
}